dsl: extract macros, remove 2 conv traits

Cargo.lock

@@ -366,7 +366,7 @@ dependencies = [
  "cfg-if",
  "libc",
  "r-efi",
- "wasi 0.14.2+wasi-0.2.4",
+ "wasi 0.14.3+wasi-0.2.4",
 ]
 
 [[package]]
@@ -874,9 +874,9 @@ dependencies = [
 
 [[package]]
 name = "regex-syntax"
-version = "0.8.5"
+version = "0.8.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2b15c43186be67a4fd63bee50d0303afffcef381492ebe2c5d87f324e1b8815c"
+checksum = "caf4aa5b0f434c91fe5c7f1ecb6a5ece2130b02ad2a590589dda5146df959001"
 
 [[package]]
 name = "rustc-demangle"
@@ -1042,7 +1042,7 @@ dependencies = [
 
 [[package]]
 name = "tengri"
-version = "0.13.0"
+version = "0.14.0"
 dependencies = [
  "crossterm 0.29.0",
  "tengri",
@@ -1056,11 +1056,11 @@ dependencies = [
 
 [[package]]
 name = "tengri_core"
-version = "0.13.0"
+version = "0.14.0"
 
 [[package]]
 name = "tengri_dsl"
-version = "0.13.0"
+version = "0.14.0"
 dependencies = [
  "const_panic",
  "itertools 0.14.0",
@@ -1073,7 +1073,7 @@ dependencies = [
 
 [[package]]
 name = "tengri_input"
-version = "0.13.0"
+version = "0.14.0"
 dependencies = [
  "tengri_core",
  "tengri_dsl",
@@ -1082,7 +1082,7 @@ dependencies = [
 
 [[package]]
 name = "tengri_output"
-version = "0.13.0"
+version = "0.14.0"
 dependencies = [
  "proptest",
  "proptest-derive",
@@ -1094,7 +1094,7 @@ dependencies = [
 
 [[package]]
 name = "tengri_proc"
-version = "0.13.0"
+version = "0.14.0"
 dependencies = [
  "heck",
  "proc-macro2",
@@ -1105,7 +1105,7 @@ dependencies = [
 
 [[package]]
 name = "tengri_tui"
-version = "0.13.0"
+version = "0.14.0"
 dependencies = [
  "atomic_float",
  "better-panic",
@@ -1146,9 +1146,9 @@ dependencies = [
 
 [[package]]
 name = "typewit"
-version = "1.12.1"
+version = "1.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "97e72ba082eeb9da9dc68ff5a2bf727ef6ce362556e8d29ec1aed3bd05e7d86a"
+checksum = "4dd91acc53c592cb800c11c83e8e7ee1d48378d05cfa33b5474f5f80c5b236bf"
 dependencies = [
  "typewit_proc_macros",
 ]
@@ -1223,11 +1223,11 @@ checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
 
 [[package]]
 name = "wasi"
-version = "0.14.2+wasi-0.2.4"
+version = "0.14.3+wasi-0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9683f9a5a998d873c0d21fcbe3c083009670149a8fab228644b8bd36b2c48cb3"
+checksum = "6a51ae83037bdd272a9e28ce236db8c07016dd0d50c27038b3f407533c030c95"
 dependencies = [
- "wit-bindgen-rt",
+ "wit-bindgen",
 ]
 
 [[package]]
@@ -1473,13 +1473,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "271414315aff87387382ec3d271b52d7ae78726f5d44ac98b4f4030c91880486"
 
 [[package]]
-name = "wit-bindgen-rt"
-version = "0.39.0"
+name = "wit-bindgen"
+version = "0.45.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6f42320e61fe2cfd34354ecb597f86f413484a798ba44a8ca1165c58d42da6c1"
-dependencies = [
- "bitflags",
-]
+checksum = "052283831dbae3d879dc7f51f3d92703a316ca49f91540417d38591826127814"
 
 [[package]]
 name = "zerocopy"

dsl/src/dsl.rs

@@ -15,8 +15,8 @@ pub(crate) use ::{
     tengri_core::*
 };
 pub(crate) use self::DslError::*;
-mod dsl_conv; pub use self::dsl_conv::*;
 #[cfg(test)] mod dsl_test;
+mod dsl_macros;
 // Trait that designates any string-like as potentially parsable DSL.
 flex_trait!(Dsl: Debug + Send + Sync + Sized {
     fn src (&self) -> DslPerhaps<&str> { unreachable!("Dsl::src default impl") }
@@ -148,54 +148,6 @@ pub const fn to_digit (c: char) -> Result<usize, DslError> {
         _ => return Err(Unexpected(c, None, Some("parse digit")))
     })
 }
-#[macro_export] macro_rules! dsl_type (($T:ident { $($trait:tt)* } {
-    pub const fn $peek:ident      $($_1:tt)?;
-    pub const fn $peek_only:ident $($_2:tt)?;
-    pub const fn $seek:ident      $($_3:tt)?;
-    pub const fn $seek_start:ident  ($source1:ident) $body1:block
-    pub const fn $seek_length:ident ($source2:ident) $body2:block
-})=>{
-    pub trait $T: Dsl { $($trait)* }
-    impl<D: Dsl> $T for D {}
-    pub const fn $seek_start  ($source1: &str) -> DslPerhaps<usize> $body1
-    pub const fn $seek_length ($source2: &str) -> DslPerhaps<usize> $body2
-    /// Find a start and length corresponding to a syntax token.
-    pub const fn $seek (source: &str) -> DslPerhaps<(usize, usize)> {
-        match $seek_start(source) {
-            Err(e) => Err(e),
-            Ok(None) => Ok(None),
-            Ok(Some(start)) => match $seek_length(str_from(source, start)) {
-                Ok(Some(length)) => Ok(Some((start, length))),
-                Ok(None) => Ok(None),
-                Err(e) => Err(e),
-            },
-        }
-    }
-    /// Find a slice corrensponding to a syntax token.
-    pub const fn $peek (source: &str) -> DslPerhaps<&str> {
-        match $seek(source) {
-            Err(e) => Err(e),
-            Ok(None) => Ok(None),
-            Ok(Some((start, length))) => Ok(Some(str_range(source, start, start + length))),
-        }
-    }
-    /// Find a slice corrensponding to a syntax token
-    /// but return an error if it isn't the only thing
-    /// in the source.
-    pub const fn $peek_only (source: &str) -> DslPerhaps<&str> {
-        match $seek(source) {
-            Err(e) => Err(e),
-            Ok(None) => Ok(None),
-            Ok(Some((start, length))) => {
-                if let Err(e) = no_trailing_non_space(source, start + length, Some("peek_only")) {
-                    Err(e)
-                } else {
-                    Ok(Some(str_range(source, start, start + length)))
-                }
-            }
-        }
-    }
-});
 
 dsl_type!(DslWord {
     fn word (&self) -> DslPerhaps<&str> {ok_flat(self.src()?.map(word_peek_only))}
@@ -278,85 +230,25 @@ fn ok_flat <T> (x: Option<DslPerhaps<T>>) -> DslPerhaps<T> {
     Ok(x.transpose()?.flatten())
 }
 
-/// Define a DSL namespace that provides values to words and expressions.
-#[macro_export] macro_rules! dsl_ns (
-    // Special form for numeric types
-    (num |$state:ident : $State: ty| $($($num:lifetime)? $Type:ty $(=> { $(
-        $pat:tt => $body:expr
-    ),* $(,)? })?;)+) => {
-        $(dsl_ns!(num |$state: $State| -> $($num)? $Type { $( $($pat => $body),* )? });)+
-    };
-    // Special form for numeric types
-    (num |$state:ident : $State: ty| -> $Type:ty { $( $pat:tt => $body:expr ),* $(,)? }) => {
-        impl<'t> DslNs<'t, $Type> for $State {
-            const WORDS: DslNsMap<'t, fn (&$State)->Perhaps<$Type>> =
-                DslNsMap::new(&[$(dsl_ns!{@word ($state: $State) -> $Type { $pat => $body }}),*]);
-            const EXPRS: DslNsMap<'t, fn (&$State, &str)->Perhaps<$Type>> =
-                DslNsMap::new(&[$(dsl_ns!{@exp ($state: $State) -> $Type { $pat => $body }}),*]);
-            fn from_literal <D: Dsl> (&self, dsl: &D) -> Perhaps<$Type> {
-                Ok(if let Some(src) = dsl.src()? {
-                    Some(to_number(src)? as $Type)
-                } else {
-                    None
-                })
-            }
-        }
-    };
-    // A namespace may resolve one or more types.
-    (|$state:ident : $State: ty| $($Type:ty $(=> { $( $pat:tt => $body:expr ),* $(,)? })? ;)+) => {
-        $(dsl_ns!(|$state: $State| -> $Type { $( $($pat => $body),* )? });)+
-    };
-    // Regular form for single type
-    (|$state:ident : $State: ty| -> $Type:ty { $( $pat:tt => $body:expr ),* $(,)? }) => {
-        impl<'t> DslNs<'t, $Type> for $State {
-            const WORDS: DslNsMap<'t, fn (&$State)->Perhaps<$Type>> =
-                DslNsMap::new(&[$(dsl_ns!{@word ($state: $State) -> $Type { $pat => $body }}),*]);
-            const EXPRS: DslNsMap<'t, fn (&$State, &str)->Perhaps<$Type>> =
-                DslNsMap::new(&[$(dsl_ns!{@exp ($state: $State) -> $Type { $pat => $body }}),*]);
-        }
-    };
-    // Symbols only.
-    (@word ($state:ident: $State:ty) -> $Type:ty {
-        $word:literal => $body:expr
-    }) => {
-        ($word, |$state|Ok(Some($body)))
-    };
-    // Expression handlers only.
-    (@exp ($state:ident: $State:ty) -> $Type:ty {
-        ($head:literal $(,$arg:ident:$ty:ty)* $(,)*) => $body:expr
-    }) => { ($head, |$state, tail: &str|{
-        $(
-            let head = tail.head()?.unwrap_or_default();
-            let tail = tail.tail()?.unwrap_or_default();
-            let $arg: $ty = if let Some(arg) = $state.from(&head)? {
-                arg
-            } else {
-                return Err(format!("{}: missing argument: {} ({}); got: {tail}",
-                    $head,
-                    stringify!($arg),
-                    stringify!($Type),
-                ).into())
-            };
-        )*
-        Ok(Some($body))
-    }) };
-    // Nothing else in symbols.
-    (@word ($state:ident: $State:ty) -> $Type:ty { $pat:tt => $body:expr }) => {
-        ("", |_|Ok(None)) // FIXME don't emit at all
-    };
-    // Nothing else in expression handlers.
-    (@exp ($state:ident: $State:ty) -> $Type:ty { $pat:tt => $body:expr }) => {
-        ("", |_, _|Ok(None)) // FIXME don't emit at all
-    };
-);
+/// Namespace mapping.
+#[derive(Debug)] pub struct DslNsMap<'t, T: Debug + 't>(pub &'t [(&'t str, T)]);
+/// Namespace mapping for [DslWord]s.
+pub type DslWords<'t, T, U> = DslNsMap<'t, fn (&'t T)->Perhaps<U>>;
+/// Namespace mapping for [DslExpr]s.
+pub type DslExprs<'t, T, U> = DslNsMap<'t, fn (&'t T, &str)->Perhaps<U>>;
+impl<'t, T: Debug + 't> DslNsMap<'t, T> {
+    /// Populate a namespace with pre-existing values.
+    pub const fn new (data: &'t [(&'t str, T)]) -> Self { Self(data) /* TODO a search trie */ }
+}
+
 
 pub trait DslNs<'t, T: 't>: 't {
     /// Known symbols.
-    const WORDS: DslNsMap<'t, fn (&Self)->Perhaps<T>> = DslNsMap::new(&[]);
+    const WORDS: DslWords<'t, Self, T> = DslNsMap::new(&[]);
     /// Known expressions.
-    const EXPRS: DslNsMap<'t, fn (&Self, &str)->Perhaps<T>> = DslNsMap::new(&[]);
+    const EXPRS: DslExprs<'t, Self, T> = DslNsMap::new(&[]);
     /// Resolve an expression or symbol.
-    fn from <D: Dsl> (&self, dsl: &D) -> Perhaps<T> {
+    fn from <D: Dsl> (&'t self, dsl: &D) -> Perhaps<T> {
         if let Ok(Some(literal)) = self.from_literal(dsl) {
             Ok(Some(literal))
         } else if let Ok(Some(meaning)) = self.from_word(dsl) {
@@ -370,14 +262,19 @@ pub trait DslNs<'t, T: 't>: 't {
         Ok(None)
     }
     /// Resolve a symbol if known.
-    fn from_word <D: Dsl> (&self, dsl: &D) -> Perhaps<T> {
+    fn from_word <D: Dsl> (&'t self, dsl: &D) -> Perhaps<T> {
         if let Some(dsl) = dsl.word()? {
-            for (key, get) in Self::WORDS.0 { if dsl == *key { return get(self) } }
+            for (key, get) in Self::WORDS.0.iter() {
+                if dsl == *key {
+                    let value = get(self);
+                    return value
+                }
+            }
         }
         return Ok(None)
     }
     /// Resolve an expression if known.
-    fn from_expr <D: Dsl> (&self, dsl: &D) -> Perhaps<T> {
+    fn from_expr <D: Dsl> (&'t self, dsl: &D) -> Perhaps<T> {
         if let Some(expr) = dsl.expr()? {
             for (key, get) in Self::EXPRS.0.iter() {
                 if Some(*key) == expr.head()? {
@@ -389,41 +286,26 @@ pub trait DslNs<'t, T: 't>: 't {
     }
 }
 
-/// Namespace mapping.
-#[derive(Debug)]
-pub struct DslNsMap<'t, T: Debug + 't>(pub &'t [(&'t str, T)]);
-impl<'t, T: Debug + 't> DslNsMap<'t, T> {
-    /// Populate a namespace with pre-existing values.
-    pub const fn new (data: &'t [(&'t str, T)]) -> Self { Self(data) /* TODO a search trie */ }
+#[deprecated]
+/// `T` + [Dsl] -> `Self`.
+pub trait FromDsl<T>: Sized {
+    fn from_dsl (state: &T, dsl: &impl Dsl) -> Perhaps<Self>;
+    fn from_dsl_or (state: &T, dsl: &impl Dsl, err: Box<dyn Error>) -> Usually<Self> {
+        Self::from_dsl(state, dsl)?.ok_or(err)
+    }
+    fn from_dsl_or_else (state: &T, dsl: &impl Dsl, err: impl Fn()->Box<dyn Error>) -> Usually<Self> {
+        Self::from_dsl(state, dsl)?.ok_or_else(err)
+    }
 }
 
-#[macro_export] macro_rules!dsl_words((|$state:ident|->$Type:ty$({
-    $($word:literal => $body:expr),* $(,)?
-})?)=>{
-    const WORDS: DslNsMap<'t, fn (&Self)->Perhaps<$Type>> = DslNsMap::new(&[$(
-        $(($word, |$state: &Self|{Ok(Some($body))})),*
-    )? ]);
-});
-
-#[macro_export] macro_rules!dsl_exprs((|$state:ident|->$Type:ty$({
-    $($name:literal ($($arg:ident:$ty:ty),* $(,)?) => $body:expr),* $(,)?
-})?)=>{
-    const EXPRS: DslNsMap<'t, fn (&Self, &str)->Perhaps<$Type>> = DslNsMap::new(&[$(
-        $(($name, |$state: &Self, tail: &str|{
-            $(
-                let head = tail.head()?.unwrap_or_default();
-                let tail = tail.tail()?.unwrap_or_default();
-                let $arg: $ty = if let Some(arg) = $state.from(&head)? {
-                    arg
-                } else {
-                    return Err(format!("{}: arg \"{}\" ({}) got: {head} {tail}",
-                        $name,
-                        stringify!($arg),
-                        stringify!($ty),
-                    ).into())
-                };
-            )*
-            Ok(Some($body))
-        })),*
-    )? ]);
-});
+#[deprecated]
+/// `self` + [Dsl] -> `T`
+pub trait DslInto<T> {
+    fn dsl_into (&self, dsl: &impl Dsl) -> Perhaps<T>;
+    fn dsl_into_or (&self, dsl: &impl Dsl, err: Box<dyn Error>) -> Usually<T> {
+        self.dsl_into(dsl)?.ok_or(err)
+    }
+    fn dsl_into_or_else (&self, dsl: &impl Dsl, err: impl Fn()->Box<dyn Error>) -> Usually<T> {
+        self.dsl_into(dsl)?.ok_or_else(err)
+    }
+}

dsl/src/dsl_conv.rs

@@ -1,59 +0,0 @@
-use crate::*;
-
-// TODO DEPRECATE:
-
-/// `T` + [Dsl] -> `Self`.
-pub trait FromDsl<T>: Sized {
-    fn from_dsl (state: &T, dsl: &impl Dsl) -> Perhaps<Self>;
-    fn from_dsl_or (state: &T, dsl: &impl Dsl, err: Box<dyn Error>) -> Usually<Self> {
-        Self::from_dsl(state, dsl)?.ok_or(err)
-    }
-    fn from_dsl_or_else (state: &T, dsl: &impl Dsl, err: impl Fn()->Box<dyn Error>) -> Usually<Self> {
-        Self::from_dsl(state, dsl)?.ok_or_else(err)
-    }
-}
-
-/// `self` + [Dsl] -> `T`
-pub trait DslInto<T> {
-    fn dsl_into (&self, dsl: &impl Dsl) -> Perhaps<T>;
-    fn dsl_into_or (&self, dsl: &impl Dsl, err: Box<dyn Error>) -> Usually<T> {
-        self.dsl_into(dsl)?.ok_or(err)
-    }
-    fn dsl_into_or_else (&self, dsl: &impl Dsl, err: impl Fn()->Box<dyn Error>) -> Usually<T> {
-        self.dsl_into(dsl)?.ok_or_else(err)
-    }
-}
-
-/// `self` + `T` -> [Dsl]
-pub trait DslFrom<T> {
-    fn dsl_from (&self, val: &T) -> Perhaps<impl Dsl>;
-    fn dsl_from_or (&self, val: &T, err: Box<dyn Error>) -> Usually<impl Dsl> {
-        self.dsl_from(val)?.ok_or(err)
-    }
-    fn dsl_from_or_else (&self, val: &T, err: impl Fn()->Box<dyn Error>) -> Usually<impl Dsl> {
-        self.dsl_from(val)?.ok_or_else(err)
-    }
-}
-
-/// `self` + `T` + -> [Dsl]
-pub trait IntoDsl<T> {
-    fn into_dsl (&self, state: &T) -> Perhaps<impl Dsl>;
-    fn into_dsl_or (&self, state: &T, err: Box<dyn Error>) -> Usually<impl Dsl> {
-        self.into_dsl(state)?.ok_or(err)
-    }
-    fn into_dsl_or_else (&self, state: &T, err: impl Fn()->Box<dyn Error>) -> Usually<impl Dsl> {
-        self.into_dsl(state)?.ok_or_else(err)
-    }
-}
-
-//impl<'s, T: FromDsl<U>, U> DslInto<'s, T> for U {
-    //fn dsl_into (&self, dsl: &impl Dsl) -> Perhaps<T> {
-        //T::from_dsl(self, dsl)
-    //}
-//}
-
-//impl<T: DslFrom<U>, U> IntoDsl<T> for U {
-    //fn into_dsl (&self, state: &T) -> Perhaps<impl Dsl> {
-        //T::dsl_from(state, self)
-    //}
-//}

dsl/src/dsl_macros.rs

@@ -0,0 +1,153 @@
+#[macro_export] macro_rules! dsl_type (($T:ident { $($trait:tt)* } {
+    pub const fn $peek:ident      $($_1:tt)?;
+    pub const fn $peek_only:ident $($_2:tt)?;
+    pub const fn $seek:ident      $($_3:tt)?;
+    pub const fn $seek_start:ident  ($source1:ident) $body1:block
+    pub const fn $seek_length:ident ($source2:ident) $body2:block
+})=>{
+    pub trait $T: Dsl { $($trait)* }
+    impl<D: Dsl> $T for D {}
+    pub const fn $seek_start  ($source1: &str) -> DslPerhaps<usize> $body1
+    pub const fn $seek_length ($source2: &str) -> DslPerhaps<usize> $body2
+    /// Find a start and length corresponding to a syntax token.
+    pub const fn $seek (source: &str) -> DslPerhaps<(usize, usize)> {
+        match $seek_start(source) {
+            Err(e) => Err(e),
+            Ok(None) => Ok(None),
+            Ok(Some(start)) => match $seek_length(str_from(source, start)) {
+                Ok(Some(length)) => Ok(Some((start, length))),
+                Ok(None) => Ok(None),
+                Err(e) => Err(e),
+            },
+        }
+    }
+    /// Find a slice corrensponding to a syntax token.
+    pub const fn $peek (source: &str) -> DslPerhaps<&str> {
+        match $seek(source) {
+            Err(e) => Err(e),
+            Ok(None) => Ok(None),
+            Ok(Some((start, length))) => Ok(Some(str_range(source, start, start + length))),
+        }
+    }
+    /// Find a slice corrensponding to a syntax token
+    /// but return an error if it isn't the only thing
+    /// in the source.
+    pub const fn $peek_only (source: &str) -> DslPerhaps<&str> {
+        match $seek(source) {
+            Err(e) => Err(e),
+            Ok(None) => Ok(None),
+            Ok(Some((start, length))) => {
+                if let Err(e) = no_trailing_non_space(source, start + length, Some("peek_only")) {
+                    Err(e)
+                } else {
+                    Ok(Some(str_range(source, start, start + length)))
+                }
+            }
+        }
+    }
+});
+
+#[macro_export] macro_rules!dsl_words(
+    (|$state:ident|->$Type:ty$({
+        $($word:literal => $body:expr),* $(,)?
+    })?)=>{
+        const WORDS: DslWords<'t, Self, $Type> = DslNsMap::new(&[$(
+            $(($word, move|$state: &Self|{Ok(Some($body))})),*
+        )? ]);
+    });
+
+#[macro_export] macro_rules!dsl_exprs(
+    (|$state:ident|->$Type:ty$({
+        $($name:literal ($($arg:ident:$ty:ty),* $(,)?) => $body:expr),* $(,)?
+    })?)=>{
+        const EXPRS: DslExprs<'t, Self, $Type> = DslNsMap::new(&[$(
+            $(($name, |$state: &Self, tail: &str|{
+                $(
+                    let head = tail.head()?.unwrap_or_default();
+                    let tail = tail.tail()?.unwrap_or_default();
+                    let $arg: $ty = if let Some(arg) = $state.from(&head)? {
+                        arg
+                    } else {
+                        return Err(format!("{}: arg \"{}\" ({}) got: {head} {tail}",
+                            $name,
+                            stringify!($arg),
+                            stringify!($ty),
+                        ).into())
+                    };
+                )*
+                Ok(Some($body))
+            })),*
+        )? ]);
+    });
+
+/// Define a DSL namespace that provides values to words and expressions.
+#[macro_export] macro_rules! dsl_ns (
+    // Special form for numeric types
+    (num |$state:ident : $State: ty| $($($num:lifetime)? $Type:ty $(=> { $(
+        $pat:tt => $body:expr
+    ),* $(,)? })?;)+) => {
+        $(dsl_ns!(num |$state: $State| -> $($num)? $Type { $( $($pat => $body),* )? });)+
+    };
+    // Special form for numeric types
+    (num |$state:ident : $State: ty| -> $Type:ty { $( $pat:tt => $body:expr ),* $(,)? }) => {
+        impl<'t> DslNs<'t, $Type> for $State {
+            const WORDS: DslWords<'t, $State, $Type> = DslNsMap::new(&[
+                $(dsl_ns!{@word ($state: $State) -> $Type { $pat => $body }}),*]);
+            const EXPRS: DslExprs<'t, $State, $Type> = DslNsMap::new(&[
+                $(dsl_ns!{@exp ($state: $State) -> $Type { $pat => $body }}),*]);
+            fn from_literal <D: Dsl> (&self, dsl: &D) -> Perhaps<$Type> {
+                Ok(if let Some(src) = dsl.src()? {
+                    Some(to_number(src)? as $Type)
+                } else {
+                    None
+                })
+            }
+        }
+    };
+    // A namespace may resolve one or more types.
+    (|$state:ident : $State: ty| $($Type:ty $(=> { $( $pat:tt => $body:expr ),* $(,)? })? ;)+) => {
+        $(dsl_ns!(|$state: $State| -> $Type { $( $($pat => $body),* )? });)+
+    };
+    // Regular form for single type
+    (|$state:ident : $State: ty| -> $Type:ty { $( $pat:tt => $body:expr ),* $(,)? }) => {
+        impl<'t> DslNs<'t, $Type> for $State {
+            const WORDS: DslNsMap<'t, fn (&$State)->Perhaps<$Type>> =
+                DslNsMap::new(&[$(dsl_ns!{@word ($state: $State) -> $Type { $pat => $body }}),*]);
+            const EXPRS: DslNsMap<'t, fn (&$State, &str)->Perhaps<$Type>> =
+                DslNsMap::new(&[$(dsl_ns!{@exp ($state: $State) -> $Type { $pat => $body }}),*]);
+        }
+    };
+    // Symbols only.
+    (@word ($state:ident: $State:ty) -> $Type:ty {
+        $word:literal => $body:expr
+    }) => {
+        ($word, |$state|Ok(Some($body)))
+    };
+    // Expression handlers only.
+    (@exp ($state:ident: $State:ty) -> $Type:ty {
+        ($head:literal $(,$arg:ident:$ty:ty)* $(,)*) => $body:expr
+    }) => { ($head, |$state, tail: &str|{
+        $(
+            let head = tail.head()?.unwrap_or_default();
+            let tail = tail.tail()?.unwrap_or_default();
+            let $arg: $ty = if let Some(arg) = $state.from(&head)? {
+                arg
+            } else {
+                return Err(format!("{}: missing argument: {} ({}); got: {tail}",
+                    $head,
+                    stringify!($arg),
+                    stringify!($Type),
+                ).into())
+            };
+        )*
+        Ok(Some($body))
+    }) };
+    // Nothing else in symbols.
+    (@word ($state:ident: $State:ty) -> $Type:ty { $pat:tt => $body:expr }) => {
+        ("", |_|Ok(None)) // FIXME don't emit at all
+    };
+    // Nothing else in expression handlers.
+    (@exp ($state:ident: $State:ty) -> $Type:ty { $pat:tt => $body:expr }) => {
+        ("", |_, _|Ok(None)) // FIXME don't emit at all
+    };
+);

output/src/layout.rs

@@ -771,33 +771,38 @@ impl<T: PartialEq, U> Memo<T, U> {
     ($buf:ident, $($rest:tt)*) => { |$buf,_,_|{ $buf.clear(); write!($buf, $($rest)*) } }
 }
 
-pub struct Stack<E, F> {
-    __: PhantomData<E>,
+pub struct Stack<'t, E, F1> {
+    __: PhantomData<&'t (E, F1)>,
     direction: Direction,
-    callback:  F
+    callback:  F1
 }
-impl<E: Output, F: Fn(&mut dyn FnMut(&dyn Render<E>)->())->()> Stack<E, F> {
-    pub fn north (callback: F) -> Self { Self::new(North, callback) }
-    pub fn south (callback: F) -> Self { Self::new(South, callback) }
-    pub fn east  (callback: F) -> Self { Self::new(East, callback)  }
-    pub fn west  (callback: F) -> Self { Self::new(West, callback)  }
-    pub fn above (callback: F) -> Self { Self::new(Above, callback) }
-    pub fn below (callback: F) -> Self { Self::new(Below, callback) }
-    pub fn new (direction: Direction, callback: F) -> Self {
+impl<'t, E, F1> Stack<'t, E, F1> where
+    E: Output,
+    F1: Fn(&mut dyn FnMut(&(dyn Render<E> + 't))) + Send + Sync,
+{
+    pub fn north (callback: F1) -> Self { Self::new(North, callback) }
+    pub fn south (callback: F1) -> Self { Self::new(South, callback) }
+    pub fn east  (callback: F1) -> Self { Self::new(East, callback)  }
+    pub fn west  (callback: F1) -> Self { Self::new(West, callback)  }
+    pub fn above (callback: F1) -> Self { Self::new(Above, callback) }
+    pub fn below (callback: F1) -> Self { Self::new(Below, callback) }
+    pub fn new (direction: Direction, callback: F1) -> Self {
         Self { direction, callback, __: Default::default(), }
     }
 }
-impl<E: Output, F: Fn(&mut dyn FnMut(&dyn Render<E>)->())->()> Content<E> for Stack<E, F> {
+impl<'t, E, F1> Content<E> for Stack<'t, E, F1> where
+    Self: 't,
+    E: Output,
+    F1: Fn(&mut dyn FnMut(&(dyn Render<E> + 't))) + Send + Sync,
+{
     fn layout (&self, to: E::Area) -> E::Area {
-        let mut x = to.x();
-        let mut y = to.y();
+        let Self { direction, callback, .. } = self;
+        let (mut x, mut y) = (to.x(), to.y());
         let (mut w_used, mut w_remaining) = (E::Unit::zero(), to.w());
         let (mut h_used, mut h_remaining) = (E::Unit::zero(), to.h());
-        (self.callback)(&mut move |component: &dyn Render<E>|{
+        callback(&mut move|component|{
             let [_, _, w, h] = component.layout([x, y, w_remaining, h_remaining].into()).xywh();
-            match self.direction {
-                North | West  => { todo!() },
-                Above | Below => {},
+            match direction {
                 South => { y           = y.plus(h);
                            h_used      = h_used.plus(h);
                            h_remaining = h_remaining.minus(h);
@@ -806,33 +811,36 @@ impl<E: Output, F: Fn(&mut dyn FnMut(&dyn Render<E>)->())->()> Content<E> for St
                            w_used      = w_used.plus(w);
                            w_remaining = w_remaining.minus(w);
                            h_used      = h_used.max(h); },
+                North | West  => { todo!() },
+                Above | Below => {},
             }
         });
-        match self.direction {
+        match direction {
             North | West  => { todo!() },
             South | East  => { [to.x(), to.y(), w_used.into(), h_used.into()].into() },
             Above | Below => { [to.x(), to.y(), to.w(), to.h()].into() },
         }
     }
     fn render (&self, to: &mut E) {
-        let mut x = to.x();
-        let mut y = to.y();
+        let Self { direction, callback, .. } = self;
+        let (mut x, mut y) = (to.x(), to.y());
         let (mut w_used, mut w_remaining) = (E::Unit::zero(), to.w());
         let (mut h_used, mut h_remaining) = (E::Unit::zero(), to.h());
-        (self.callback)(&mut move |component: &dyn Render<E>|{
+        callback(&mut move|component|{
             let layout = component.layout([x, y, w_remaining, h_remaining].into());
-            match self.direction {
-                Above | Below => { to.place(layout, component);  }
+            match direction {
+                South => {
+                    y           = y.plus(layout.h());
+                    h_remaining = h_remaining.minus(layout.h());
+                    h_used      = h_used.plus(layout.h()) },
+                East  => {
+                    x           = x.plus(layout.w());
+                    w_remaining = w_remaining.minus(layout.w());
+                    w_used      = w_used.plus(layout.h()) },
                 North | West  => { todo!() },
-                South => { y           = y.plus(layout.h());
-                           h_remaining = h_remaining.minus(layout.h());
-                           h_used      = h_used.plus(layout.h());
-                           to.place(layout, component); },
-                East  => { x           = x.plus(layout.w());
-                           w_remaining = w_remaining.minus(layout.w());
-                           w_used      = w_used.plus(layout.h());
-                           to.place(layout, component); },
-            }
+                Above | Below => {}
+            };
+            to.place(layout, component);
         });
     }
 }
@@ -881,66 +889,45 @@ impl<'a, E, A, B, I, F, G> Map<E, A, B, I, F, G> where
     }
 }
 
-impl<'a, E, A, B, I, F> Map<E, A, Push<E::Unit, Align<Fixed<E::Unit, Fill<B>>>>, I, F, fn(A, usize)->B>
-where
-    E: Output,
-    B: Render<E>,
-    I: Iterator<Item = A> + Send + Sync + 'a,
-    F: Fn() -> I + Send + Sync + 'a
-{
-    pub const fn east (
-        size:     E::Unit,
-        get_iter: F,
-        get_item: impl Fn(A, usize)->B + Send + Sync
-    ) -> Map<
-        E, A,
-        Push<E::Unit, Align<Fixed<E::Unit, B>>>,
-        I, F,
-        impl Fn(A, usize)->Push<E::Unit, Align<Fixed<E::Unit, B>>> + Send + Sync
-    > {
-        Map {
-            __: PhantomData,
-            get_iter,
-            get_item: move |item: A, index: usize|{
-                // FIXME: multiply
-                let mut push: E::Unit = E::Unit::from(0u16);
-                for _ in 0..index {
-                    push = push + size;
-                }
-                Push::x(push, Align::w(Fixed::x(size, get_item(item, index))))
-            }
-        }
-    }
-
-    pub const fn south (
-        size:     E::Unit,
-        get_iter: F,
-        get_item: impl Fn(A, usize)->B + Send + Sync
-    ) -> Map<
-        E, A,
-        Push<E::Unit, Align<Fixed<E::Unit, B>>>,
-        I, F,
-        impl Fn(A, usize)->Push<E::Unit, Align<Fixed<E::Unit, B>>> + Send + Sync
+macro_rules! impl_map_direction (($name:ident, $axis:ident, $align:ident)=>{
+    impl<'a, E, A, B, I, F> Map<
+        E, A, Push<E::Unit, Align<Fixed<E::Unit, Fill<B>>>>, I, F, fn(A, usize)->B
     > where
         E: Output,
         B: Render<E>,
         I: Iterator<Item = A> + Send + Sync + 'a,
         F: Fn() -> I + Send + Sync + 'a
     {
-        Map {
-            __: PhantomData,
-            get_iter,
-            get_item: move |item: A, index: usize|{
-                // FIXME: multiply
-                let mut push: E::Unit = E::Unit::from(0u16);
-                for _ in 0..index {
-                    push = push + size;
+        pub const fn $name (
+            size:     E::Unit,
+            get_iter: F,
+            get_item: impl Fn(A, usize)->B + Send + Sync
+        ) -> Map<
+            E, A,
+            Push<E::Unit, Align<Fixed<E::Unit, B>>>,
+            I, F,
+            impl Fn(A, usize)->Push<E::Unit, Align<Fixed<E::Unit, B>>> + Send + Sync
+        > {
+            Map {
+                __: PhantomData,
+                get_iter,
+                get_item: move |item: A, index: usize|{
+                    // FIXME: multiply
+                    let mut push: E::Unit = E::Unit::from(0u16);
+                    for _ in 0..index {
+                        push = push + size;
+                    }
+                    Push::$axis(push, Align::$align(Fixed::$axis(size, get_item(item, index))))
                 }
-                Push::y(push, Align::n(Fixed::y(size, get_item(item, index))))
             }
         }
     }
-}
+});
+
+impl_map_direction!(east,  x, w);
+impl_map_direction!(south, y, n);
+impl_map_direction!(west,  x, e);
+impl_map_direction!(north, y, s);
 
 impl<'a, E, A, B, I, F, G> Content<E> for Map<E, A, B, I, F, G> where
     E: Output,